masterrigger1 2 #1 June 10, 2013 Quote Now do the same for a well used piece of Spectra,. Note the results. You will find that the used piece will have a lesser distance of differential. Never said it didn't, just refuting the implication that spectra loses its elasticity over time. That was the implication I got from your post. I am refuting your claim that it does not and even offered the simple test to show that it does. Quote The first thing that needs to be addressed is the root cause, not the fix to the root cause. You just restated my point here but I think you are under the impression that the root cause is line elasticity. Actually, the root cause is Spectra and all of it's issues. Trim, lack of/low elasticity,etc... Quote Data has already shown that if you have the same jumper, same equipment, same person packing, and only change line type, the openings are better. Period. I have thousands of case studies in the field...still... Change the word line with pilot chute, line trim and locking stoe e-band breaking point and the statement is still also true. Deployment is a system. It is not just lines! Looking at only one aspect and and rejecting further examination..... well that's offensive to me! Negative, You offer a totally different scenario. Let's put it to you a different way. Take all brand new gear, change the lines from Spectra to Technora and you will have better openings. Again, vivid, real life test data here. As far as the one aspect comment; I have already looked at the other components and now focused on the culprit. Quote have thousands of case studies in the field...still... This is exactly the anecdotal evidence I'm talking about. It is weak observation and therefore weak science. Real life data is a casual observation!...Give us a break! Quote There is veracity to the claim that Dacron can give you attenuation on low forces and the difference in the "out of trim tendencies" also lead to the conclusion that it does a better job. (I've stated this several times) But..... Because the stretch is nonlinear, the advantage diminishes as forces increase. Just so you know, Dacron is not my first choice of line material. It is by far though, better that Spectra. QuoteNow I would love to go into how heightened neurological responses in skydivers cause an increase pattern recognition in the anterior para cingulate cortex creating false pattern recognition (yes I can site studies) but I will leave you with two points. First, There are many causes to hard openings outside of line attenuation, it is not the cause and it is fairly insignificant in high forces. Secondly, I will again state (what you have stated) that we need to look for the root cause. And finally, just because you believe Dacron is better, doesn't mean it's the answer. You need to question your bias. The definition of attenuation is actually the loss of forces though a type of medium BTW. While I could care less about studies of social interaction and parts of the brain that promote or deny responses, I do care about my work. My "bias" is based on absolutes. MELSkyworks Parachute Service, LLC www.Skyworksparachuteservice.com Quote Share this post Link to post Share on other sites
JohnSherman 1 #2 June 10, 2013 QuoteTake all brand new gear, change the lines from Spectra to Technora and you will have better openings. Again, vivid, real life test data here. MEL, Would you please provide (to this forum) the Data Graph for Altitude and acceleration from the data logger used for these "real life test data". Additionally, I would be interested in the canopy and D-bag type/configuration used in these tests. Also how many test were made and what are the distributed results. JS Quote Share this post Link to post Share on other sites
teason 0 #3 June 10, 2013 I don't even know how to reply here. The root cause is spectra?!? Look, both lines have their pros and cons. Wearability, attenuation and so on. To suggest that spectra is the root cause of hard openings is ridiculous! I tried to get into that by talking about how the line reacts at low and high forces to illustrate the advantage is diminished at high forces and therefore not the answer to catastrophic force like the ones experienced here. It seems you have to position that hard opening will be ok if you have Dacron. My view is how can we prevent hard opening. It's proactive vs reactive. There are other things that mitigate opening forces. (And now I have to use mitigate because the more common albeit not entirely accurate "attenuation" will start a war on semantics.) And you should be interested in neurological response to stress because it create false conclusions, especially when your personal studies involve "hearing from some guy" regardless of their jump numbers. (It was even studied specifically in skydivers) My bias is never absolute, may be wrong and is willing to change.I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet. Quote Share this post Link to post Share on other sites
FB1609 0 #4 June 10, 2013 My hardest opening ever was on a 7 cell F111, I think maybe a Cruiselite or similar. It was borrowed gear that I didn't pack, throw out, racer, 80's gear. I almost lost consciousness, before AADs were popular. So I would imagine any canopy/line type has the potential to cause fatal injury. I think looking into a shock absorbing system would be well worth the effort, no matter how rare. I'm sure most people here have had at least one cracker where they saw stars. Quote Share this post Link to post Share on other sites
masterrigger1 2 #5 June 11, 2013 Quote MEL, Would you please provide (to this forum) the Data Graph for Altitude and acceleration from the data logger used for these "real life test data". Additionally, I would be interested in the canopy and D-bag type/configuration used in these tests. Also how many test were made and what are the distributed results. John, It is obvious that not matter what answer we/I give you. you will not be satisfied with that answer. You have a data logger, a parachute company and are right next to a major DZ. Go ahead and build a system, jump it, log the information, then change line set to Technora and do the same test. Then post that info (to this forum). I already have my findings, you don't believe me, so prove me wrong. MELSkyworks Parachute Service, LLC www.Skyworksparachuteservice.com Quote Share this post Link to post Share on other sites
JohnSherman 1 #6 June 12, 2013 Present your data for peer review otherwise it can not be considered. You made a statement now back it up. To refuse to answer because you don't think I will believe you is preposterus. It's not for me to judge in any event but for everyone else to see the data and make up their own mind. That's how these forums work. Quote Share this post Link to post Share on other sites
JeffCa 0 #7 June 12, 2013 JohnShermanPresent your data for peer review otherwise it can not be considered. You made a statement now back it up. To refuse to answer because you don't think I will believe you is preposterus. It's not for me to judge in any event but for everyone else to see the data and make up their own mind. That's how these forums work. Hi masterrigger1, I agree with John here. You two are not the only people reading this. I'm new and trying to learn as much as I can. If you feel you have some experimental results that will be of benefit to the community, I respectfully request that you please do present them. "So many fatalities and injuries are caused by decisions jumpers make before even getting into the aircraft. Skydiving can be safe AND fun at the same time...Honest." - Bill Booth Quote Share this post Link to post Share on other sites
masterrigger1 2 #8 June 12, 2013 Quote resent your data for peer review otherwise it can not be considered. You made a statement now back it up. To refuse to answer because you don't think I will believe you is preposterus. It's not for me to judge in any event but for everyone else to see the data and make up their own mind. That's how these forums work. John, You laid claim that the lines had nothing to do with it in the beginning. Go back and look. Quote Don't try to blame this on line type. The difference between the line types is not sufficient to do the damage Mike sustained. Based on your claim that the line type had nothing to do with it; present that data. The results of my work are being jumped and used everyday. Go over to the DZ and look at what people are actually jumping. Also, did you use a data logger on the speed-bag video that you posted? Deployment looks a bit long.... Quote It's not for me to judge in any event but for everyone else to see the data and make up their own mind. That's how these forums work. Exactly! MELSkyworks Parachute Service, LLC www.Skyworksparachuteservice.com Quote Share this post Link to post Share on other sites
masterrigger1 2 #9 June 12, 2013 Quote Hi masterrigger1, I agree with John here. You two are not the only people reading this. I'm new and trying to learn as much as I can. If you feel you have some experimental results that will be of benefit to the community, I respectfully request that you please do present them. Understand. Since you are new, you probably need to go back through the forums and search my posts regarding line type. Then compare what was said in those forums in many years past, what manufacturers where saying/using then and actually look at what they are using now. I think that should answer most of your questions. MELSkyworks Parachute Service, LLC www.Skyworksparachuteservice.com Quote Share this post Link to post Share on other sites
